Boeing 727
The Boeing 727 is a mid-size narrow-body three-engine jet aircraft built by Boeing Commercial Airplanes. It can carry 149 to 189 passengers and later models can fly up to nonstop. Intended for short and medium-length flights, the 727 can use fairly short runways at smaller airports. It has three Pratt & Whitney JT8D engines below the T-tail, one on each side of the fuselage with a center engine that connects through an S-duct to an inlet at the base of the fin. The 727 is Boeing's only trijet aircraft. The 727 followed the 707 quad-jet airliner with which it shares its upper fuselage cross-section and cockpit design. The 727-100 first flew in February 1963 and entered service with Eastern Air Lines in February 1964; the stretched 727-200 flew in July 1967 and entered service with Northeast Airlines that December. The 727 became a mainstay of airlines' domestic route networks and was also used on short- and medium-range international routes. Passenger, freighter, and convertible versions of the 727 were built. The 727 was heavily produced into the 1970s; the last 727 was completed in 1984. In July 2011, 23 727-100s and 227 727-200s were in airline service. Airport noise regulations have led to 727s being equipped with hush kits. Development The Boeing 727 design was a compromise among United Airlines, American Airlines, and Eastern Air Lines requirements for a jet airliner to serve smaller cities with shorter runways and fewer passengers. United Airlines wanted a four-engine aircraft for its flights to high-altitude airports, especially its hub at Stapleton International Airport at Denver, Colorado. American, which was operating the four-engine Boeing 707 and Boeing 720, wanted a twin-engine aircraft for efficiency. Eastern wanted a third engine for its overwater flights to the Caribbean, since at that time twin-engine commercial flights were limited by regulations to routes with 60-minute maximum flying time to an airport (see ETOPS/LROPS). Eventually the airlines agreed on a trijet. In 1959 Lord Douglas, chairman of British European Airways (BEA), suggested that Boeing and de Havilland Aircraft Company (later Hawker Siddeley) work together on their trijet designs, the 727 and D.H.121 Trident, respectively.Connors, p. 355. The two designs had a similar layout, the 727 being slightly larger. At that time Boeing intended to use three Allison AR963 turbofan engines, license-built versions of the Rolls-Royce RB163 Spey used by the Trident."Boeing 727" ANALYSING THE 727Boeing's Trimotor: BACKGROUND TO THE DEVELOPMENT OF THE 727 Boeing and de Havilland each sent engineers to the other company's locations to evaluate each other's designs, but Boeing eventually decided against the joint venture.Connors, p. 357. De Havilland had wanted Boeing to license-build the D.H.121, while Boeing felt that the aircraft needed to be designed for the American market, with six-abreast seating and the ability to use runways as short as 4,500 ft. In 1960 Pratt & Whitney was looking for a customer for its new JT8D turbofan design study, based on its J52 (JT8A) turbojet,Connors, pp. 348–349. while United and Eastern were interested in a Pratt & Whitney alternative to the RB163 Spey.Connors, p. 350. Once Pratt & Whitney agreed to go ahead with development of the JT8D, Eddie Rickenbacker, Chairman of the Board of Eastern, told Boeing that the airline preferred the JT8D for its 727s. Boeing had not offered the JT8D as it was about 1,000 lbs heavier than the RB163, though slightly more powerful; the RB163 was also further along in development than the JT8D. Boeing reluctantly agreed to offer the JT8D as an option on the 727 and it later became the sole powerplant.Connors, p. 352. With high-lift devicesEden, Paul. (Ed). Civil Aircraft Today. 2008: Amber Books, pp. 72–3. on its wing the 727 could use shorter runways than most earlier jets (e.g. the 4800-ft runway at Key West). Later 727 models were stretched to carry more passengersEden 2008, pp. 74–5. and replaced earlier jet airliners such as the Boeing 707 and Douglas DC-8 as well as aging prop airliners such as the DC-4, DC-6, DC-7 and the Lockheed Constellations on domestic routes. For over a decade more 727s were built per year than any other jet airliner; in 1984 production ended with 1,832 built and 1,831 delivered, the highest total for any jet airliner until the 737 surpassed it in the early 1990s.Norris and Wagner. Modern Boeing Jetliners, pp. 12–3. Motorbooks International, 1999. Design in September 1981]] (1978).]] The airliner's middle engine (engine 2) at the very rear of the fuselage gets air from an inlet ahead of the vertical fin through an S-shaped duct."Boeing 727 series. Aircraft & Powerplant Corner." This S-duct proved to be troublesome in that flow distortion in the duct induced a surge in the centerline engine on the take-off of the first flight of the 727-100.Case Study in Aircraft Design; the Boeing 727, American Institute of Aeronautics and Astronautics Professional Study Series, September 1978. This was fixed by the addition of several large vortex generators in the inside of the first bend of the duct. The 727 was designed for smaller airports, so independence from ground facilities was an important requirement. This led to one of the 727's most distinctive features: the built-in airstair that opens from the rear underbelly of the fuselage, which initially could be opened in flight. A hijacker known as D. B. Cooper parachuted from the back of a 727 as it was flying over the Pacific Northwest. Boeing subsequently modified the design with the Cooper vane so that the airstair could not be lowered in flight. Another innovation was the auxiliary power unit (APU), which allowed electrical and air-conditioning systems to run independent of a ground-based power supply, without having to start one of the main engines. An unusual design feature is that the APU is mounted in a hole in the keel beam web, in the main landing gear bay. The 727 is equipped with a retractable tail skid that is designed to protect the aircraft in the event of an over-rotation on takeoff. The 727's fuselage has an outer diameter of . This allows six-abreast seating (three per side) and a single aisle when wide coach-class seats are installed. An unusual feature of the fuselage is the 10 inch difference between the lower lobe forward and aft of the wing as the higher fuselage height of the center-section was simply retained towards the rear. 727-200 at Jorge Wilsterman Airport. The rear air stairs are visible at the 727's tail.]] Nose wheel brakes were available as an option to reduce braking distance on landing, which provided reductions in braking distances of up to 150 m.Lufthansa. Operating Manual Boeing 727, pp. 1.4.32-1, 4.3.4-2. The 727 proved to be such a reliable and versatile airliner that it came to form the core of many start-up airlines' fleets. The 727 was successful with airlines worldwide partly because it could use smaller runways while still flying medium-range routes. This allowed airlines to carry passengers from cities with large populations but smaller airports to worldwide tourist destinations. One of the features that gave the 727 its ability to land on shorter runways was its unique wing design. With no wing-mounted engines, leading-edge devices (Krueger, or hinged, flaps on the inner wing and extendable leading edge slats out to the wingtip) and trailing-edge lift enhancement equipment (triple-slotted,Boeing: http://www.boeing.com/commercial/727family/index.html aft-moving flaps) could be used on the entire wing. Together these high-lift devices produced a maximum wing lift coefficient of 3.0 (based on the flap-retracted wing area). The 727 was stable at very low speeds compared to other early jets, but some domestic carriers learned after review of various accidents that the 40-degree flaps setting could result in a higher-than-desired sink rate or a stall on final approach. These carriers' Pilots' Operation Handbooks disallowed using more than 30 degrees of flaps on the 727, even going so far as installing plates on the flap slot to prevent selection of more than 30 degrees of flaps. Noise The 727 is one of the noisiest commercial jetliners, categorized as Stage 2 by the U.S. Noise Control Act of 1972, which mandated the gradual introduction of quieter Stage 3 aircraft. The 727's JT8D jet engines use older low-bypass turbofan technology, whereas Stage 3 aircraft utilize the more efficient and quieter high-bypass turbofan design. When the Stage 3 requirement was being proposed, Boeing engineers analyzed the possibility of incorporating quieter engines on the 727. They determined that the JT8D-200 engine could be used on the two side-mounted pylons, but the structural changes to fit the larger-diameter engine ( fan diameter in the JT8D-200 compared to in the JT8D-7) into the fuselage at the number two engine location were prohibitive. Current regulations require that a 727 in commercial service must be retrofitted with a hush kit to reduce engine noise to Stage 3 levels. One such hush kit is offered by FedEx,Fedex Hushkit webpage and has been purchased by over 60 customers.Fedex Hushkit Customer List After-market winglets kits, originally developed by Valsan Partners and later marketed by Quiet Wing Corp.Flight International hush kit survey have been installed on many 727s to reduce noise at lower speeds, as well as to reduce fuel consumption. Kelowna Flightcraft's maintenance division in Canada has installed winglets on Donald Trump's private 727-100. In addition, Raisbeck Engineering developed packages to enable 727s to meet the Stage 3 noise requirements. These packages managed to get light- and medium-weight 727s to meet Stage 3 with simple changes to the flap and slat schedules. For heavier-weight 727s, exhaust mixers must be added to meet Stage 3. American Airlines ordered and took delivery of 52 Raisbeck 727 Stage 3 systems. Other customers have included TWA, Pan Am, Air Algérie, TAME and many smaller airlines.James Raisbeck: Breathing New Technology into Aviation Retrieved July 25, 2011Boeing 727 Stage 3 Noise Reduction Kits Retrieved July 25, 2011 From September 1, 2010, 727 jetliners (including those with a hush kit) are banned from some Australian airports due to noise. Operational history In addition to domestic flights of medium range, the 727 was popular with international passenger airlines. The range of flights it could cover (and the additional safety added by the third engine) meant that the 727 proved efficient for short- to medium-range international flights in areas around the world. Prior to its introduction, four-engine jets or propeller-driven airliners were required for transoceanic service. The 727 also proved popular with cargo airlines and charter airlines. FedEx Express introduced 727s in 1978. 727s were the backbone of its fleet until recently, but FedEx is now phasing them out in favor of the Boeing 757. Many cargo airlines worldwide employ the 727 as a workhorse, since, as it is being phased out of U.S. domestic service due to noise regulations, it becomes available to overseas users in areas where such noise regulations have not yet been instituted. Charter airlines Sun Country, Champion Air, and Ryan International Airlines all started with 727 aircraft. ]] The 727 saw some military use as well. Since the aft stair could be opened in flight, the Central Intelligence Agency used them to drop agents and supplies behind enemy lines in Vietnam. The 727 has proven to be popular where the airline serves airports with gravel, or otherwise lightly improved runways. The Canadian airline First Air, for example, previously used a 727-100C to service the communities of Resolute Bay and Arctic Bay in Nunavut, whose Resolute Bay Airport and former Nanisivik Airport both have gravel runways. The high mounted engines greatly reduce the risk of foreign object damage. According to the Boeing Jetliner Databook, the Justice Prisoner and Alien Transportation System, also known as 'Con Air', currently uses four 727 aircraft to transport persons in legal custody between prisons, detaining centers, courthouses, and other places to where they must be transported A military version, the Boeing C-22 was operated as a medium-range transport aircraft by the Air National Guard and National Guard Bureau to airlift personnel. A total of three C-22B's were in use, all assigned to the 201st Airlift Squadron, District of Columbia Air National Guard. with opened cargo door (at Miami International Airport, 1998).]] At the turn of the 21st century, the 727 was in service with a few airline fleets; however, due to changes by the U.S. FAA and the ICAO in over-water flight requirements, most major airlines had already begun to switch to twin-engine aircraft, which are more fuel-efficient and quieter than the three-engine 727. Also, the 727 was one of the last airliners in service to have a three-person flight crew, including a flight engineer, a crew member whose tasks have been largely automated on newer airliners. Faced with higher fuel costs (although all major United States airlines phased them out immediately prior to the oil price increases since 2003), lower passenger volumes due to the post-9/11 economic climate, increasing restrictions on airport noise, and the extra expenses of maintaining older planes and paying flight engineers' salaries, most major airlines have phased 727s out of their fleets. Delta Air Lines, the last major U.S. carrier to do so, retired its last 727 from scheduled service in April 2003. Northwest Airlines retired its last 727 from charter service in June 2003. The 727 is still flying for some smaller start-up airlines, cargo airlines, and charter airlines, and it is also sometimes used as a private means of transportation. The official replacement for the 727 in Boeing's lineup was the Boeing 757; however, the smallest 757 variant, the 757-200, is significantly larger than the 727-200, so many airlines replaced their 727s with either the 737-800 or the Airbus A320; both are closer in size to the 727-200. , a total of 109 Boeing 727s were in commercial service with 34 airlines. Of these, 5 were 727-100s and 104 were -200s."2013 World Airliner Census", p. 49. Variants 727-100]] Data from:''Boeing Aircraft since 1916 There are two series of 727; the initial 100 (originally only two figures as in −30) was launched in 1960 and entered service in February 1964. The 727-200 series was launched in 1965 and entered service in December 1967. 727-100 The first 727-00 flew on February 9, 1963 and FAA type approval was awarded on December 24 of that year, with initial delivery to United Airlines on October 29, 1963, to allow pilot training to commence. The first 727 passenger service was flown by Eastern Air Lines on February 1, 1964, between Miami, Florida, Washington, D.C., and Philadelphia, Pennsylvania. A total of 571 727-00/100 series aircraft were delivered (407 -100s, 53 -100Cs, and 111 -100QCs), the last in October 1972. One 727-100 was retained by Boeing, bringing total production to 572.Airclaims Jet Programs 1995 The −100 designation is a retroactive one to distinguish the original short-body version. Aircraft for United Airlines were delivered as 727-22, for American Airlines as 727-23 and so on, not −122 and −123 and retained these designations even after the advent of the 727-200. ;727-100C Convertible passenger cargo version. Additional freight door and strengthened floor and floor beams. Three alternate fits: *94 mixed-class passengers *52 mixed-class passengers and four cargo pallets (22,700 lb, 10,297 kg) *Eight cargo pallets (38,000 lb, 17,237 kg) ;727-100QC QC stands for Quick Change. This is similar to the Convertible version with a roller-bearing floor for palletised galley and seating and/or cargo to allow much faster changeover time (30 minutes). ;727-100QF QF stands for Quiet Freighter. A cargo conversion for United Parcel Service, re-engined with Stage III-compliant Rolls-Royce Tay turbofans. ;Boeing C-22A :A single 727-30 acquired from the Federal Aviation Administration, which was originally delivered to Lufthansa. This aircraft served mostly with Southern Command flying from Panama City / Howard Air Force Base. ;Boeing C-22B :Four 727-35 aircraft acquired from National Airways by the USAF for transporting Air National Guard and National Guard personnel. 727-200 Stretched version of the 727-100. The -200 is longer (153 feet, 2 inches, 46.7 m) than the −100 (133 feet, 2 inches, 40.6 m). A ten-foot (3-meter) fuselage section ("plug") was added in front of the wings and another ten-foot fuselage section was added behind them. The wing span and height remain the same on both the −100 and −200 ( and , respectively). The original 727-200 had the same max gross weight as the 727-100; however, as the aircraft evolved, a series of higher gross weights and more powerful engines was introduced along with other improvements, and, from line number 881, 727-200s are dubbed −200 Advanced. The aircraft gross weight eventually increased from for the latest versions. The dorsal intake of the number two engine was also redesigned to be round in shape, rather than oval as it was on the 100 series. The first 727-200 flew on July 27, 1967 and received FAA certification on November 30, 1967. The first delivery was made on December 14, 1967 to Northeast Airlines. A total of 310 727-200s were delivered before giving way to the 727-200Adv in 1972. ;727-200C Convertible passenger cargo version. One was built. 727-200Adv]] ;727-200 Advanced MTOW and range increased. Also, cabin improvements. ;727-200F Advanced A freighter version of the 727-200 Advanced became available in 1981 designated the Series 200F Advanced powered by the Pratt & Whitney JT8D-17A engines and featured a strengthened fuselage structure, an 11 ft 2 inch by 7 ft 2 inch forward main deck freight door and a windowless cabin. This was the last production variant of the 727 to be developed by Boeing, and 15 aircraft were built, all for Federal Express. The last 727 aircraft to be completed by Boeing was the Series 200F Advanced for Federal Express. ;Super 27 Speed increased by , due to replacement of the two side engines with the JT8D-217 or the JT8D-219, which are also found on many MD-80s, along with the addition of hush kits to the center engine. Winglets were added to some of these aircraft to increase fuel efficiency. This modification was originally developed by Valsan Partners, but was later marketed by Quiet Wing Technologies in Redmond, Washington.Flight International hush kit survey ;Boeing C-22C :A single 727-212 aircraft operated by the USAF Operators , 188 Boeing 727 aircraft (all variants) are in commercial airline, private and government service. Most airlines have small numbers but the following operate five or more aircraft:. As of March 2014 Iran Air uses 2 727-200's and are the only major airline that still use 727-200s in their fleet *Amerijet International (6) *Asia Pacific Airlines (3) *Cargojet Airways (10) *Kalitta Charters (7) *Kelowna Flightcraft Air Charter (13) *Líneas Aéreas Suramericanas (8) *Rio Linhas Aéreas (8) *Total Linhas Aéreas (6) *Transmile Air Services (4) *Iran Aseman Airlines (6) Government, military, and other operators In addition, the 727 has seen sporadic government use, having flown for the Belgian, Yugoslavian, Mexican, New Zealand, and Panama air forces, among the small group of government agencies that have used it. The United States military used the 727 as a military transport, designated as the C-22. ; *Military of Benin (1) ; *Bolivian Air Force (Transporte Aereo Militar) (1) ; *Force Aérienne de Burkina Faso (1) ; *Colombian government *Colombian Air Force (2) ; *Force Aérienne du Congo (4) ; *Djibouti Air Force ; *Ecuadorian Air Force (3) ; *Iraqi government, Salah Aldin (1) ; *Mexican Air Force (5) *Federal Preventive Police (4) ; *Mongolian Air Force (2) Specifications Data from Boeing Aircraft since 1916 Accidents and incidents As of 2010, a total of 325 incidents involving 727s had occurred, including 112 hull-loss accidents"Boeing 727 Accident summary", Aviation-Safety.net, May 5, 2007. Retrieved July 13, 2008. resulting in a total of 3,783 fatalities. The 727 has also been in 178 hijackings involving 345 fatalities."Boeing 727 Accident Statistics", Aviation-Safety.net, December 3, 2007. Retrieved July 13, 2008. Orders and deliveries Source: 727 Model Summary Boeing Aircraft on display The following U.S. museums have Boeing 727s on display or in storage: *Carolinas Aviation Museum 727 cockpit on display, ex-Roush 727 in storage at Charlotte-Douglas International Airport *Museum of Flight First 727 completed, still in restoration stage. To be flown to museum when finished. Another 727 is currently on display. *National Museum of Commercial Aviation, Atlanta, Georgia – ex-FedEx 727 in storage at Atlanta airport. *Museum of Science and Industry, Chicago, ex-United Airlines 727 * Canadian Warplane Heritage Museum A cockpit portion of a Boeing 727 in FedEx livery (ex-United Airlines) is on display. *Kansas Aviation Museum, Wichita, Kansas- ex-FedEx 727-100C on display. *Outagamie County Regional Airport, Appleton, Wisconsin- ex-FedEx 727-200 on display *Museum of Flying, Santa Monica, California- nose portion of ex-FedEx 727 on display *Florida Air Museum, Lakeland, Florida- ex-FedEx 727 on display See also *Hawker Siddeley Trident *McDonnell Douglas DC-9 *Tupolev Tu-154 *List of airliners *Trijet *2012 Boeing 727 crash experiment References * * "World Airliner Census". Flight International, Volume 184, Number 5403, 13–19 August 2013, pp. 40–58. * External links *Boeing.com 727 Family *727 prototype on rbogash.com *Boeing-727.com site *Fatal Boeing 727 Events on Airsafe.com 727 Category:Trijets Category:1960s United States airliners